FLUORESCENCE BEHAVIOR OF PYRENE UNDER POLARITY CHANGES OF ITS MICROENVIRONMENT IN THE PRESENCE OF CTAB AGGREGATES

HERMET, M.; BERNIK, D.; MORCELLE, S.R.; BAKAS, L.

Congreso; XLII Brazilian Biophysical Society Congress; 2017

Brazilian Biophysical Society Congress

The synthesis and purification of new surfactants devoted to pharmaceuticaltechnology or to molecular biology studies is costly in time and resources aswell as the biochemical assays to prove their efficacy in the task they areobtained for. In many cases proficiency at very low amounts are required. Theefficiency of a given surfactant molecule depends on a series of factors amongwhich critical micelle concentration (CMC) and the structure of the obtainedmicelles are crucial. CMC values at the submillimolar range are often observedfor surfactants with bulky head-groups and long hydrophobic tails. A fast, easyand reliable methodology to find out the CMC of new surfactants is needed.Steady state fluorescent measurements are affordable in most of researchlaboratories, and many fluorescent molecular probes can afford this task. In this work we describe results obtained with the well-known pyrene probe and thesurfactant CTAB (also known as cetrimide). CTAB was chosen given its netpositive charge and its polar head not too voluminous, having some structuralsimilarities with novel arginine-based cationic surfactants synthesized in ourgroup by means of a biocatalytic strategy [1,2]. New information was obtainedand the quality of the data acquired with different equipment is compared. Inthe course of data analysis, some of the assumptions inherent to pyrenephotochemistry in its interaction with surfactants are reasserted, and someothers are open to a broader perspective.[1]Fait, M.E.; Garrote, G.L.; Clapés, P.; Tanco, S.; Lorenzo, J.; Morcelle, S.R.(2015). ?Biocatalytic synthesis, antimicrobial properties and toxicity studies of arginine derivative surfactants?. Amino Acids. Editorial: Springer. ISSN: 0939-4451. 47 (7):1465-1477. DOI: 10.1007/500726-015-1979-0. [2]Fait, M.E.;Hermet, M.; Comelles, F.; Clapés, P.; Álvarez, A.; Prieto, E.; Morcelle, S.R.;Bakás, L. (2016). Micellar attack of arginine-based surfactants towards theerythrocyte membrane. III Reunión de Latin American Federation of BiophysicalSocieties-IX Iberoamerican Congress of Biophysics-XLV Reunión de laSociedad Argentina de Biofísica. San Miguel de Tucumán, Argentina,noviembre de 2016.